Mercurial > hg
annotate mercurial/compat.h @ 30308:d500ddae7494
bdiff: don't check border condition in loop
`plast = a + len - 1`. So, this "for" loop iterates from "a" to "plast",
inclusive. So, `p == plast` can only be true on the final iteration
of the loop. So checking for it on every loop iteration is wasteful.
This patch simply decreases the upper bound of the loop by 1 and
adds an explicit check after iteration for the `p == plast` case.
We can't simply add 1 to the initial value for "i" because that
doesn't do the correct thing on empty input strings.
`perfbdiff -m 3041e4d59df2` on the Firefox repo becomes significantly
faster:
! wall 0.072763 comb 0.070000 user 0.070000 sys 0.000000 (best of 100)
! wall 0.053221 comb 0.060000 user 0.060000 sys 0.000000 (best of 100)
For the curious, this code has its origins in 8b067bde6679, which is
the changeset that introduced bdiff.c in 2005.
Also, GNU diffutils is able to perform a similar line-based diff in
under 20ms. So there's likely more perf wins to be found in this code.
One of them is the hashing algorithm. But it looks like mpm spent
some time testing hash collisions in d0c48891dd4a. I'd like to do the
same before switching away from lyhash, just to be on the safe side.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 06 Nov 2016 00:37:50 -0700 |
parents | 7b22599dcb85 |
children | f4433f2713d0 |
rev | line source |
---|---|
29444
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
1 #ifndef _HG_COMPAT_H_ |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
2 #define _HG_COMPAT_H_ |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
3 |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
4 #ifdef _WIN32 |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
5 #ifdef _MSC_VER |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
6 /* msvc 6.0 has problems */ |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
7 #define inline __inline |
29521
83147ff53112
compat: provide a declaration of ssize_t, for MS windows
Maciej Fijalkowski <fijall@gmail.com>
parents:
29444
diff
changeset
|
8 #if defined(_WIN64) |
83147ff53112
compat: provide a declaration of ssize_t, for MS windows
Maciej Fijalkowski <fijall@gmail.com>
parents:
29444
diff
changeset
|
9 typedef __int64 ssize_t; |
83147ff53112
compat: provide a declaration of ssize_t, for MS windows
Maciej Fijalkowski <fijall@gmail.com>
parents:
29444
diff
changeset
|
10 #else |
29549
7b22599dcb85
compat: define ssize_t as int on 32bit Windows, silences C4142 warning
Yuya Nishihara <yuya@tcha.org>
parents:
29521
diff
changeset
|
11 typedef int ssize_t; |
29521
83147ff53112
compat: provide a declaration of ssize_t, for MS windows
Maciej Fijalkowski <fijall@gmail.com>
parents:
29444
diff
changeset
|
12 #endif |
29444
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
13 typedef signed char int8_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
14 typedef short int16_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
15 typedef long int32_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
16 typedef __int64 int64_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
17 typedef unsigned char uint8_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
18 typedef unsigned short uint16_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
19 typedef unsigned long uint32_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
20 typedef unsigned __int64 uint64_t; |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
21 #else |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
22 #include <stdint.h> |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
23 #endif |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
24 #else |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
25 /* not windows */ |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
26 #include <sys/types.h> |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
27 #if defined __BEOS__ && !defined __HAIKU__ |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
28 #include <ByteOrder.h> |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
29 #else |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
30 #include <arpa/inet.h> |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
31 #endif |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
32 #include <inttypes.h> |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
33 #endif |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
34 |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
35 #if defined __hpux || defined __SUNPRO_C || defined _AIX |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
36 #define inline |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
37 #endif |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
38 |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
39 #ifdef __linux |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
40 #define inline __inline |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
41 #endif |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
42 |
284d742e5611
internals: move the bitmanipulation routines into its own file
Maciej Fijalkowski <fijall@gmail.com>
parents:
diff
changeset
|
43 #endif |